It is really hard to say how to fix it just looking at a picture.
It looks like you have the same cladding on the outside and inside.
I would probably make sure these are 2 separate Building Materials - the outside stronger than the inside.
Generally if the strength decrease towards the inside of the wall you will have less trouble.
That is not to say that is how it has to be done.
If the above does not help can you post a screen shot of your wall composites.
Then select those walls and open the Building Materials dialogue box.
Press the symbol above the column that show the tick if the BM is being used so the list sorts 'by use' and show a screen shot of that too.
Then we can see what is going on.
Barry.
One of the forum moderators.
Versions 6.5 to 27
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